Brittlestars overlying coralline crusts, Parasmittina trispinosa and Caryophyllia smithii on wave-exposed circalittoral rock

English name: Brittlestars overlying coralline crusts, Parasmittina trispinosa and Caryophyllia smithii on wave-exposed circalittoral rock

Quick facts

EUNIS habitat type code A4.2121
Bern Convention Included in a Resolution 4 habitat type at a higher level (A4)

Description (English)

This variant is typically found on the upper faces of wave-exposed circalittoral bedrock or boulders subject to moderately strong to weak tidal streams, on open coasts. However, the depth at which the variant occurs means that wave action is not so severe on the seabed as to displace the dense mat of brittlestars that covers the seabed. Ophiothrix fragilis is usually the most dominant species in shallow water, with Ophiocomina nigra usually found amongst them, but sometimes becoming the dominant species in deeper water. Although brittlestar biotopes are typically species-poor, the underlying fauna in this variant is relatively diverse and resembles that of A4.2122. Species such as the anemone Urticina felina, the cup coral Caryophyllia smithii, and the anemone Corynactis viridis may occasionally be present. There may also be sparse clumps of various hydroids including Halecium halecinum, Nemertesia antennina, Nemertesia ramosa, Sertularella gayi and Abietinaria abietina. Soft coral Alcyonium digitatum is occasionally present and there may be sparse specimens of the sponges Cliona celata and Polymastia boletiformis. In addition, various echinoderms such as Asterias rubens, Antedon bifida, Echinus esculentus, Henricia oculata, Marthasterias glacialis and Luidia ciliaris may be observed. The barnacle Balanus crenatus and the polychaete Pomatoceros triqueter may be seen attached to any available space on the bedrock and boulders not smothered by brittlestars. Bryozoan crusts such as Parasmittina trispinosa may also be present.
Situation: Wave-exposed seabed composed of bedrock ridges and/or boulder or cobble slope. Shallower than this biotope, the lower infralittoral kelp park is dominated by Laminaria hyperborea. A dense understorey may be present, containing Antedon spp., Phycodrys rubens and Plocamium cartilagineum.

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Algae Laminaria hyperborea
Algae Phycodrys rubens
Algae Plocamium cartilagineum
Invertebrates Abietinaria abietina
Invertebrates Alcyonium digitatum
Invertebrates Antedon bifida
Invertebrates Asterias rubens
Invertebrates Balanus crenatus
Invertebrates Caryophyllia smithii
Invertebrates Cliona celata
Invertebrates Corynactis viridis
Invertebrates Echinus esculentus
Invertebrates Henricia oculata
Invertebrates Luidia ciliaris
Invertebrates Marthasterias glacialis
Invertebrates Nemertesia antennina
Invertebrates Nemertesia ramosa
Invertebrates Ophiocomina nigra
Invertebrates Ophiothrix fragilis
Invertebrates Parasmittina trispinosa
Invertebrates Polymastia boletiformis
Invertebrates Pomatoceros triqueter
Invertebrates Sertularella gayi
Invertebrates Urticina felina
Species scientific name English common name Species group
Laminaria hyperborea Algae
Phycodrys rubens Algae
Plocamium cartilagineum Algae
Abietinaria abietina Invertebrates
Alcyonium digitatum Invertebrates
Antedon bifida Invertebrates
Asterias rubens Invertebrates
Balanus crenatus Invertebrates
Caryophyllia smithii Invertebrates
Cliona celata Invertebrates
Corynactis viridis Invertebrates
Echinus esculentus Invertebrates
Henricia oculata Invertebrates
Luidia ciliaris Invertebrates
Marthasterias glacialis Invertebrates
Nemertesia antennina Invertebrates
Nemertesia ramosa Invertebrates
Ophiocomina nigra Invertebrates
Ophiothrix fragilis Invertebrates
Parasmittina trispinosa Invertebrates
Polymastia boletiformis Invertebrates
Pomatoceros triqueter Invertebrates
Sertularella gayi Invertebrates
Urticina felina Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 CR.MCR.EcCr.CarSp.Bri Brittlestars overlying coralline crusts, <I>Parasmittina trispinosa</I> and <I>Caryophyllia smithii</I> on wave-exposed circalittoral rock source
CORINE Land Cover 5.2.3. Sea and ocean n/a
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 200410 A4.2121 Brittlestars overlying coralline crusts, Parasmittina trispinosa and Caryophyllia smithii on wave-exposed circalittoral rock same
EUNIS Habitat Classification 200308 A3.651 Ophiothrix fragilis and/or Ophiocomina nigra beds on slightly tide-swept circalittoral rock or mixed substrata wider
EUNIS Habitat Classification 200202 A3.651 Ophiothrix fragilis and/or Ophiocomina nigra beds on slightly tide-swept circalittoral rock or mixed substrata overlap
EUNIS Habitat Classification 199910 A3.651 Ophiothrix fragilis and/or Ophiocomina nigra beds on slightly tide-swept circalittoral rock or mixed substrata overlap
MNCR BioMar 97.06 (Britain & Ireland) MCR.Bri.Oph Ophiothrix fragilis and/or Ophiocomina nigra beds on slightly tide-swept circalittoral rock or mixed substrata overlap
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